The present application claims priority based on CN 02125224.6, filed on Jul. 17, 2002, which is incorporated herein by reference in its entirety and for all purposes.
The present invention relates to a novel silicon ether compound, a method for the preparation thereof and use thereof in the polymerization of olefins.
W O 00/63261 discloses external electron donor compounds useful in olefin polymerization, i.e. silicon compounds having a general formula R11aR12bSi(OR13)c, wherein a and b are integer from 0 to 2, c is integer from 1 to 3, and the sum of a+b+c is 4, R11, R12 and R13 are independently C1-C18 hydrocarbyl which optionally contains heteroatom. The preferred are those silicon compounds in which a is 1, b is 1, c is 2, at least one of R11 and R12 are selected from the group consisting of branched alkyl, alkenyl, alkylene, cycloalkyl and aryl, having from 3 to 10 carbon atoms and containing optionally heteroatom, and R13 is C1-C10 alkyl, especially methyl, for example, cyclohexylmethyldimethoxysilane. The also preferred are those silicon compounds in which a is 0, b is 1, c is 3, R12 is branched alkyl or cycloalkyl, containing optionally heteroatom, and R13 is methyl, for example, cyclohexyltrimethoxysilane and the like.
It is noted that when c is 1, the silicon compounds having the general formula R11aR12bSi(OR13)c are not deemed as good external electron donor compound. In the prior art, xcex3-trihydrocarbylsilyloxy-ether compounds are never used as external electron donor compounds in olefin polymerization. However, the inventors surprisingly found that xcex3-trihydrocarbylsilyloxy-ether or -silicon ether compounds exhibit good properties when used as external electron donor compounds in olefin polymerization. 9-hydrocarbyloxymethyl-9-(trihydrocarbylsilyl)oxymethyl-fluorene compounds and 9,9-bis(trihydrocarbylsilyloxymethyl)-fluorene compounds are specific xcex3-trihydrocarbylsilyloxy-ether or -silicon ether compounds, and hitherto, no literature reporting them as well as the preparation thereof was found.